thermal spraying
(rus. газотермическое напыление)
— a method of applying metal-ceramic or polymer coatings up to a thickness of several millimetres by transferring condensed particles in a gas or plasma flow.

The particles forming the coating usually are sized at several microns. High speed and monodispersity of particles usually improves the quality of the coating manifested in such parameters as porosity, degree of binding between the particles, microhardness and surface roughness.

There are many methods of thermal spraying, the most common of which are gas-flame spraying, plasma spraying and electric arc spraying. This group of methods also includes cold powder spraying, where a coating is formed due to high kinetic energy of solid particles. Source materials for such coatings are metal, polymer, ceramic and metal-ceramic powders and, in some cases, metal wire.